Datasheet

467
11011B–ATARM–21-Feb-12
SAM3N
467
11011B–ATARM–21-Feb-12
SAM3N
28.7 Functional Description
28.7.1 Transfer Format
The data put on the TWD line must be 8 bits long. Data is transferred MSB first; each byte must
be followed by an acknowledgement. The number of bytes per transfer is unlimited (see Figure
28-4).
Each transfer begins with a START condition and terminates with a STOP condition (see Figure
28-3).
• A high-to-low transition on the TWD line while TWCK is high defines the START condition.
• A low-to-high transition on the TWD line while TWCK is high defines a STOP condition.
Figure 28-3. START and STOP Conditions
Figure 28-4. Transfer Format
28.7.2 Modes of Operation
The TWI has six modes of operations:
• Master transmitter mode
• Master receiver mode
• Multi-master transmitter mode
• Multi-master receiver mode
• Slave transmitter mode
• Slave receiver mode
These modes are described in the following chapters.
TWD
TWCK
Start Stop
TWD
TWCK
Start Address R/W Ack Data Ack Data Ack Stop